Wednesday, Jul 23, 2014
A large landslide occurred from the southern wall of the Askja caldera yesterday night. The slide caused a large flood wave in the Öskjuvatn lake that also swept into the famous Viti crater. ... [more]
Saturday, May 03, 2014
A swarm of shallow earthquakes at 2-10 km depth has started under the Herðubreið volcano about 12 km NE of the Askja caldera. The largest earthquakes so far were 2 magnitude 3.2 and 3.0 events. ... [more]
Askja volcanoAskja is a large basaltic central volcano that forms the Dyngjufjöll massif. It is truncated by three overlapping calderas, the largest of which is 8 km wide and may have been produced primarily from subglacial ring-fracture eruptions rather than by subsidence.
Background:A major rhyolitic explosive eruption from Dyngjufjöll about 10,000 years ago was in part associated with the formation of Askja caldera. Many postglacial eruptions also occurred along the ring-fracture. A major explosive eruption on the SE caldera margin in 1875 was one of Iceland's largest during historical time. It resulted in the formation of a smaller 4.5-km-wide caldera, now filled by Öskjuvatn lake, that truncates the rim of the larger central caldera. The 100-km-long Askja fissure swarm, which includes the Sveinagja graben, is also related to the Askja volcanic system, as are several small shield volcanoes such as Kollatadyngja. Twentieth-century eruptions at Askja have produced lava flows from vents located mostly near Öskjuvatn lake.
Source: GVP, Smithsonian Institution
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